A good rule to know when training for a marathon is that you will generally have enough endurance to finish a race that is 3 times your average daily distance. Tammy
wants to be able to run at least the standard marathon distance of 26.2 miles. The
length of her current daily run is about 4 miles. To the nearest hundredth, by how
many miles should she increase her daily run to meet her goal?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?